Can You Use Fungicide and Fertilizer at the Same Time?

Find out if you can apply fungicide and fertilizer simultaneously and which types of fertilizer go well with fungicide.

Sean Stratton | Updated February 8, 2023
father and son fertilizing in a gardenin

Fungicide and fertilizer can be applied simultaneously, depending on the specific products being used and the timing of application. Check the label of the fungicide and fertilizer to ensure that they are compatible and that the application rates and timing will not cause any negative interactions.

Not every kind of fungicide can be applied with fertilizers simultaneously. The only type of fungicide you can apply with fertilizer is the one that needs to be irrigated in.

You need to water your lawn after fertilizing to make the fertilizer work effectively on the soil. So, if you have a fungicide that also needs water, then these two are great matches for each other. And in this case, you can hit two birds with one stone because you need to use water once, which will suffice for both.

So, the best fungicide for this case is a granular fungicide because it needs water to activate. If you choose a granular fertilizer and a granular fungicide, you can apply both at the same time using the same lawn spreader.

First, measure the required amount of fungicide and fertilizer for your lawn. Then mix them well. After that, spread them together using a spreader. This will save you from applying the fertilizer and fungicide separately.

Can I Fertilize after Applying Fungicide?

Yes, you can apply fertilizer after fungicide application. If you’re using a granular fungicide, you don’t need to fertilize later, you can do that on the same day. But if you used liquid fungicide on the lawn, you must wait a few days before fertilizing.

Also Read: Fertilizing Azaleas (A Complete Guide)

Should You Fertilize a Lawn that Has Fungus?

This can have two answers. If this question comes to mind due to thinking about whether a fertilizer itself can kill the fungus or not, I would say ‘no’. You see fertilizers are not meant to kill your lawn fungus. If the fungus has already invaded your lawn, fertilizer is not enough to fight it.

First, you need to use a proper fungicide to eliminate fungus from your lawn and then think of doing something else. But if you’re thinking about whether a fertilizer will make the fungus yield in your lawn and make things worse, this requires further discussion.

Your lawn can get affected by fungus for both over-fertilizing and under-fertilizing. So, if you use too much fertilizer on an infected lawn, the results may not be satisfactory.

So, for this, I would advise you to check the information provided by the fertilizer manufacturer. If you’re hesitant to apply fertilizer on the lawn with unclear information, you can ask a local lawn care expert before picking that specific fertilizer.

How Long Should I Wait to Fertilize after Fungicide?

The waiting time for applying fertilizer after fungicide application depends on the type of fungicide you are using. If you have used a granular fungicide, you don’t need to wait for a single day, you can apply the fertilizer right away; on the same day. You can say this is the advantage of using granular fungicide.

If you’re in a rush to apply fertilizer after using a fungicide, you can pick a granular fungicide. But if you have applied a liquid type fungicide, you need to wait for a few days before applying fertilizer. Wait about three to five days after applying the fungicide.

This is because you need to water the lawn to activate the fertilizer and when you water the lawn, it will hamper the work of the fungicide. And waiting after applying fungicide is actually a good thing because you will be able to determine whether the product is working or not.

So, if you have time in hand, you can wait for like 7 to 14 days after the fungicide application to determine how it is working on your lawn.

Which Fertilizer Should Not Be Mixed with Fungicide?

Before answering this question, let’s answer another question that can come the other way around, mixing what type of fungicide with fertilizer is not a good idea? The answer is liquid fungicide. We have said earlier that you need to water your yard to make the fertilizer work effectively.

If you use liquid fungicides and water your lawn afterward, there are chances of the fungicides getting washed off or getting leached into the ground. As a result, your fungicides will not work as effectively as expected.

So, if you applied a liquid type fungicide first, wait at least three days before applying fertilizer. Now coming to the answer to our question, since watering after fertilizing is beneficial, you are encouraged to water after applying fertilizer. Watering will remove the fertilizer from the grass blades and help make its way to the soil so that it can start providing nutrients to the plants.

If you let the fertilizer sit for a long time without proper watering, you may end up with burnt grass. So, instead of the fertilizer, you need to focus on the fungicide that will not get affected by watering after fertilizer application.

What Fertilizer Can Be Applied at the Same Time with Fungicide?

Granular fertilizer can be applied with granular fungicide all together. These two make a great combination to apply in your yard. You don’t need to apply the fertilizer and fungicide separately. Both granular fungicide and granular fertilizer can be mixed together and spread at the same time. This saves your time and makes your work easier.

Final Thoughts

If you choose granular fertilizer and granular fungicide for your lawn, you can mix them together and spread them using a lawn spreader at the same time.

Written by Sean Stratton

Sean Stratton

Hi, I'm Sean, the senior editor here at Fertilizer Pick. I grew up on a farm in North Carolina and have grown fruits, vegetables, and trees since childhood. While I no longer live on a farm today, I still enjoy spending time on my garden and sharing my knowledge with friends and fellow garden enthusiasts.